宏观移动接触线流动的广义准普适亚网格模型

中文摘要 AI 辅助

由于固体表面上无滑移边界条件引起的应力奇异性以及该现象固有的多尺度特性，移动接触线流动的预测颇具挑战性。解析微观长度尺度会因极高的计算成本而使宏观流动的数值模拟难以处理。对于宏观流动，经济且可预测的数值解需要一种无需针对特定案例校准的亚网格模型，以缓解否则会出现的网格依赖性。我们展示了将Cox的匹配渐近关系与经验接触角模型耦合，以获得准普适的亚网格模型。该耦合需要一次性了解用于构建经验模型的实验的观测长度尺度或分辨率。本模型无需指定诸如微观滑移长度和壁面接触角等唯象参数，从而能够对此类流动进行预测性模拟。我们通过在不同雷诺数和韦伯数范围内，针对三种不同接触角模型，在前进和后退接触线运动情景下进行轴对称液滴铺展模拟，展示了网格依赖性误差的降低。

英文摘要

Predictions of moving contact line flows are challenging due to the stress singularity associated with the no-slip boundary condition on solid surfaces and the inherently multiscale nature of the phenomenon. Resolving the microscopic length scale renders the numerical simulations intractable for macroscopic flows due to extremely high computational costs. Affordable and predictive numerical solutions for macroscopic flows require a subgrid model, free of case-specific calibration, that mitigates the grid-dependence observed otherwise. We demonstrate a coupling between Cox's matched asymptotic relation and the empirical contact angle models to obtain a quasi-universal subgrid model. The coupling requires a one-time knowledge of the observation length scale or resolution of the experiments used to formulate the empirical models. The present model eliminates the need for prescribing phenomenological parameters such as the microscopic slip length and wall contact angle, allowing for the predictive simulations of such flows. We demonstrate the reduction in error due to grid-dependence by conducting axisymmetric simulations of droplet spreading for a wide range of Reynolds and Weber numbers for three different contact angle models in the advancing and receding contact line motion scenarios.

发表机构

• Indian Institute of Science Education and Research Bhopal（印度科学教育研究学院博帕尔分校）

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